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Shera CA. Swept Along: Measuring Otoacoustic Emissions Using Continuously Varying Stimuli. J Assoc Res Otolaryngol 2024; 25:91-102. [PMID: 38409555 PMCID: PMC11018600 DOI: 10.1007/s10162-024-00934-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 01/31/2024] [Indexed: 02/28/2024] Open
Abstract
At the 2004 Midwinter Meeting of the Association for Research in Otolaryngology, Glenis Long and her colleagues introduced a method for measuring distortion-product otoacoustic emissions (DPOAEs) using primary-tone stimuli whose instantaneous frequencies vary continuously with time. In contrast to standard OAE measurement methods, in which emissions are measured in the sinusoidal steady state using discrete tones of well-defined frequency, the swept-tone method sweeps across frequency, often at rates exceeding 1 oct/s. The resulting response waveforms are then analyzed using an appropriate filter (e.g., by least-squares fitting). Although introduced as a convenient way of studying DPOAE fine structure by separating the total OAE into distortion and reflection components, the swept-tone method has since been extended to stimulus-frequency emissions and has proved an efficient and valuable tool for probing cochlear mechanics. One day-a long time coming-swept tones may even find their way into the audiology clinic.
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Affiliation(s)
- Christopher A Shera
- Caruso Department of Otolaryngology, University of Southern California, Los Angeles, CA, 90033, USA.
- Department of Physics & Astronomy, University of Southern California, Los Angeles, CA, 90033, USA.
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Jamos AM, Chertoff ME, Kaf WA, Ferraro JA. Medial Olivocochlear Reflex Effect on Cochlear Response in Humans: Elicitor Side and Level. J Am Acad Audiol 2021; 32:366-373. [PMID: 34731904 DOI: 10.1055/s-0041-1728649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Understanding the functional differences between crossed and uncrossed medial olivocochlear (MOC) neurons has been of interest to researchers for decades. Previous reports revealed conflicting results about which MOC pathway, crossed or uncrossed, is stronger in humans. Both crossed and uncrossed MOC neurons synapse at the base of the outer hair cells (OHCs) in each ear. OHCs generate the cochlear microphonic, which is a major contributor to the cochlear response (CR) PURPOSE: The current study investigated the effects of eliciting the crossed and uncrossed MOC reflex (MOCR) on CR in humans with three levels of noise. RESEARCH DESIGN Normal-hearing, young adults (n = 16) participated in this study. The CR was recorded using 500 Hz tone-burst stimuli presented at 80 dB nHL. To examine the crossed and uncrossed MOCR, CR was recorded without and with continuous ipsilateral or contralateral broadband noise (BBN) at three levels (40, 50, and 60 dB SPL). DATA ANALYSIS Analysis of the CR was completed using the amplitude of the response extracted using fast Fourier transform. Statistical analysis was completed using repeated measures analysis of variance and post-hoc analysis. RESULTS Compared with baseline, the presentation of BBN, specifically contralaterally, resulted in CR enhancement with no significant difference as a function of the three BBN levels. Greater enhancement of the CR amplitude was observed with contralateral than ipsilateral BBN elicitor. CONCLUSIONS The current findings suggest that a contralateral elicitor of the uncrossed MOC pathway results in a larger CR amplitude enhancement compared with an ipsilateral elicitor of the crossed MOC pathway, regardless of the elicitor level. Eliciting the MOCR appears to modulate the OHCs function. Furthermore, assessing the MOCR with the 500 Hz CR with BBN elicitors at moderate levels should separate its effects (i.e., increase response amplitude) from those associated with the middle ear muscle reflex (i.e., reduce response amplitude).
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Affiliation(s)
- Abdullah M Jamos
- Department of Communication Sciences and Disorders, Missouri State University, Springfield, Missouri
| | - Mark E Chertoff
- Department of Hearing and Speech, University of Kansas Medical Center, Kansas City, Kansas
| | - Wafaa A Kaf
- Department of Communication Sciences and Disorders, Missouri State University, Springfield, Missouri
| | - John A Ferraro
- Department of Hearing and Speech, University of Kansas Medical Center, Kansas City, Kansas
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Bell A, Jedrzejczak WW. Muscles in and around the ear as the source of "physiological noise" during auditory selective attention: A review and novel synthesis. Eur J Neurosci 2021; 53:2726-2739. [PMID: 33484588 DOI: 10.1111/ejn.15122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 01/17/2021] [Indexed: 12/01/2022]
Abstract
The sensitivity of the auditory system is regulated via two major efferent pathways: the medial olivocochlear system that connects to the outer hair cells, and by the middle ear muscles-the tensor tympani and stapedius. The role of the former system in suppressing otoacoustic emissions has been extensively studied, but that of the complementary network has not. In studies of selective attention, decreases in otoacoustic emissions from contralateral stimulation have been ascribed to the medial olivocochlear system, but the acknowledged problem is that the results can be confounded by parallel muscle activity. Here, the potential role of the muscle system is examined through a wide but not exhaustive review of the selective attention literature, and the unifying hypothesis is made that the prominent "physiological noise" detected in such experiments, which is reduced during attention, is the sound produced by the muscles in proximity to the ear-including the middle ear muscles. All muscles produce low-frequency sound during contraction, but the implications for selective attention experiments-in which muscles near the ear are likely to be active-have not been adequately considered. This review and synthesis suggests that selective attention may reduce physiological noise in the ear canal by reducing the activity of muscles close to the ear. Indeed, such an experiment has already been done, but the significance of its findings have not been widely appreciated. Further sets of experiments are needed in this area.
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Affiliation(s)
- Andrew Bell
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
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Jamos AM, Kaf WA, Chertoff ME, Ferraro JA. Human medial olivocochlear reflex: Contralateral activation effect on low and high frequency cochlear response. Hear Res 2020; 389:107925. [DOI: 10.1016/j.heares.2020.107925] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 02/07/2020] [Accepted: 02/13/2020] [Indexed: 10/25/2022]
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Marks KL, Siegel JH. Differentiating Middle Ear and Medial Olivocochlear Effects on Transient-Evoked Otoacoustic Emissions. J Assoc Res Otolaryngol 2017; 18:529-542. [PMID: 28432471 DOI: 10.1007/s10162-017-0621-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 03/22/2017] [Indexed: 10/19/2022] Open
Abstract
The response of the inner ear is modulated by the middle ear muscle (MEM) and olivocochlear (OC) efferent systems. Both systems can be activated reflexively by acoustic stimuli delivered to one or both ears. The acoustic middle ear muscle reflex (MEMR) controls the transmission of acoustic signals through the middle ear, while reflex activation of the medial component of the olivocochlear system (the MOCR) modulates cochlear mechanics. The relative prominence of the two efferent systems varies widely between species. Measuring the effect of either of these systems can be confounded by simultaneously activating the other. We describe a simple, sensitive online method that can identify the effects both systems have on otoacoustic emissions (OAEs) evoked by transient stimuli such as clicks or tone pips (TEOAEs). The method detects directly in the time domain the changes in the stimulus and/or emission pressures caused by contralateral noise. Measurements in human participants are consistent with other reports that the threshold for MOCR activation is consistently lower than for MEMR. The method appears to control for drift and subject-generated noise well enough to avoid the need for post hoc processing, making it promising for application in animal experiments (even if awake) and in the hearing clinic.
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Affiliation(s)
- Kendra L Marks
- Department of Communication Sciences and Disorders, School of Communication, Northwestern University, 2240 Campus Drive, Evanston, IL, 60208-2952, USA
| | - Jonathan H Siegel
- Department of Communication Sciences and Disorders, School of Communication, Northwestern University, 2240 Campus Drive, Evanston, IL, 60208-2952, USA.
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Estimation of Round-Trip Outer-Middle Ear Gain Using DPOAEs. J Assoc Res Otolaryngol 2016; 18:121-138. [PMID: 27796594 DOI: 10.1007/s10162-016-0592-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 09/20/2016] [Indexed: 10/20/2022] Open
Abstract
The reported research introduces a noninvasive approach to estimate round-trip outer-middle ear pressure gain using distortion product otoacoustic emissions (DPOAEs). Our ability to hear depends primarily on sound waves traveling through the outer and middle ear toward the inner ear. The role of the outer and middle ear in sound transmission is particularly important for otoacoustic emissions (OAEs), which are sound signals generated in a healthy cochlea and recorded by a sensitive microphone placed in the ear canal. OAEs are used to evaluate the health and function of the cochlea; however, they are also affected by outer and middle ear characteristics. To better assess cochlear health using OAEs, it is critical to quantify the effect of the outer and middle ear on sound transmission. DPOAEs were obtained in two conditions: (i) two-tone and (ii) three-tone. In the two-tone condition, DPOAEs were generated by presenting two primary tones in the ear canal. In the three-tone condition, DPOAEs at the same frequencies (as in the two-tone condition) were generated by the interaction of the lower frequency primary tone in the two-tone condition with a distortion product generated by the interaction of two other external tones. Considering how the primary tones and DPOAEs of the aforementioned conditions were affected by the forward and reverse outer-middle ear transmission, an estimate of the round-trip outer-middle ear pressure gain was obtained. The round-trip outer-middle ear gain estimates ranged from -39 to -17 dB between 1 and 3.3 kHz.
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AlMakadma HA, Henin S, Prieve BA, Dyab WM, Long GR. Frequency-change in DPOAE evoked by 1 s/octave sweeping primaries in newborns and adults. Hear Res 2015; 328:157-65. [PMID: 26318364 DOI: 10.1016/j.heares.2015.08.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 08/17/2015] [Accepted: 08/21/2015] [Indexed: 10/23/2022]
Abstract
Distortion product otoacoustic emissions (DPOAE) in newborns and adults were evoked by sweeping primaries up and down in frequency at 1 s/octave. Sweeping up and down in frequency resulted in changes in the amplitude vs. frequency functions of the composite DPOAE and its two major components. In addition, DPOAE component phases differed slightly between the up- and down-swept conditions. The changes in amplitude vs. frequency functions were quantified using a covariate correlation technique, yielding single-valued estimates of the magnitude of the frequency changes. Separate analyses were performed for the entire DPOAE frequency range and split into low and high frequency ranges. There were consistent changes in newborn and adult composite DPOAEs and reflection components, but not generator components. Adults had significant frequency changes in the composite DPOAE for all frequency ranges and in the reflection component for the entire frequency range. Newborns had significant frequency change in the reflection component for all frequency ranges. Differences in frequency change between adults and newborns may stem from developmental changes in cochlear processing. Alignment of the component phase differences between the up- and down-swept conditions resulted in elimination of frequency-change in reconstructed composite DPOAEs.
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Affiliation(s)
- Hammam A AlMakadma
- Department of Communication Sciences and Disorders, Syracuse University, 621 Skytop Road, Suite 1200, Syracuse, NY 13210, United States.
| | - Simon Henin
- Speech-Language-Hearing Sciences, Graduate School and University Center, City University of New York, 365 Fifth Avenue, NY 10016, United States.
| | - Beth A Prieve
- Department of Communication Sciences and Disorders, Syracuse University, 621 Skytop Road, Suite 1200, Syracuse, NY 13210, United States.
| | - Walid M Dyab
- L.C. Smith College of Engineering and Computer Science, 621 Skytop Road, Syracuse University, Syracuse, NY 13244, United States.
| | - Glenis R Long
- Speech-Language-Hearing Sciences, Graduate School and University Center, City University of New York, 365 Fifth Avenue, NY 10016, United States.
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Walsh KP, Pasanen EG, McFadden D. Changes in otoacoustic emissions during selective auditory and visual attention. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2015; 137:2737-57. [PMID: 25994703 PMCID: PMC4441704 DOI: 10.1121/1.4919350] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 04/16/2015] [Accepted: 04/17/2015] [Indexed: 06/04/2023]
Abstract
Previous studies have demonstrated that the otoacoustic emissions (OAEs) measured during behavioral tasks can have different magnitudes when subjects are attending selectively or not attending. The implication is that the cognitive and perceptual demands of a task can affect the first neural stage of auditory processing-the sensory receptors themselves. However, the directions of the reported attentional effects have been inconsistent, the magnitudes of the observed differences typically have been small, and comparisons across studies have been made difficult by significant procedural differences. In this study, a nonlinear version of the stimulus-frequency OAE (SFOAE), called the nSFOAE, was used to measure cochlear responses from human subjects while they simultaneously performed behavioral tasks requiring selective auditory attention (dichotic or diotic listening), selective visual attention, or relative inattention. Within subjects, the differences in nSFOAE magnitude between inattention and attention conditions were about 2-3 dB for both auditory and visual modalities, and the effect sizes for the differences typically were large for both nSFOAE magnitude and phase. These results reveal that the cochlear efferent reflex is differentially active during selective attention and inattention, for both auditory and visual tasks, although they do not reveal how attention is improved when efferent activity is greater.
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Affiliation(s)
- Kyle P Walsh
- Department of Psychology and Center for Perceptual Systems, University of Texas, 1 University Station A8000, Austin, Texas 78712-0187, USA
| | - Edward G Pasanen
- Department of Psychology and Center for Perceptual Systems, University of Texas, 1 University Station A8000, Austin, Texas 78712-0187, USA
| | - Dennis McFadden
- Department of Psychology and Center for Perceptual Systems, University of Texas, 1 University Station A8000, Austin, Texas 78712-0187, USA
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Marshall L, Lapsley Miller JA, Guinan JJ, Shera CA, Reed CM, Perez ZD, Delhorne LA, Boege P. Otoacoustic-emission-based medial-olivocochlear reflex assays for humans. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2014; 136:2697-713. [PMID: 25373970 PMCID: PMC5392105 DOI: 10.1121/1.4896745] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 09/15/2014] [Accepted: 09/18/2014] [Indexed: 05/20/2023]
Abstract
Otoacoustic emission (OAE) tests of the medial-olivocochlear reflex (MOCR) in humans were assessed for viability as clinical assays. Two reflection-source OAEs [TEOAEs: transient-evoked otoacoustic emissions evoked by a 47 dB sound pressure level (SPL) chirp; and discrete-tone SFOAEs: stimulus-frequency otoacoustic emissions evoked by 40 dB SPL tones, and assessed with a 60 dB SPL suppressor] were compared in 27 normal-hearing adults. The MOCR elicitor was a 60 dB SPL contralateral broadband noise. An estimate of MOCR strength, MOCR%, was defined as the vector difference between OAEs measured with and without the elicitor, normalized by OAE magnitude (without elicitor). An MOCR was reliably detected in most ears. Within subjects, MOCR strength was correlated across frequency bands and across OAE type. The ratio of across-subject variability to within-subject variability ranged from 2 to 15, with wideband TEOAEs and averaged SFOAEs giving the highest ratios. MOCR strength in individual ears was reliably classified into low, normal, and high groups. SFOAEs using 1.5 to 2 kHz tones and TEOAEs in the 0.5 to 2.5 kHz band gave the best statistical results. TEOAEs had more clinical advantages. Both assays could be made faster for clinical applications, such as screening for individual susceptibility to acoustic trauma in a hearing-conservation program.
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Affiliation(s)
- Lynne Marshall
- Naval Submarine Medical Research Laboratory, Box 900, Subase NLON, Box 900, Groton, Connecticut 06349-5900
| | - Judi A Lapsley Miller
- Naval Submarine Medical Research Laboratory, Box 900, Subase NLON, Box 900, Groton, Connecticut 06349-5900
| | - John J Guinan
- Eaton-Peabody Laboratory of Auditory Physiology, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, Massachusetts 02114
| | - Christopher A Shera
- Eaton-Peabody Laboratory of Auditory Physiology, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, Massachusetts 02114
| | - Charlotte M Reed
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307
| | - Zachary D Perez
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307
| | - Lorraine A Delhorne
- Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307
| | - Paul Boege
- Consultant, Hirschanger 17, D-82319, Starnberg, Germany
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